This invention relates to safety arrangements for internal combustion engines having a circulating coolant.
Safety arrangements for internal combustion engines which are arranged to prevent damage to the engine resulting from overheating are relatively old. One device of this type is described in German Patent No. 967 248. In that safety device, a thermostat detects the engine temperature and responds to overheating by controlling the maximum throttle deflection through a mechanical connection. After a selected engine temperature has been reached, the thermostat limits the deflection of the throttle and thus reduces the fuel supply.
However, rapid actuation of the limitation of the load and/or the speed of the internal combustion engine is required when an abnormality in the cooling system occurs. This is especially true in evaporative cooling systems where cooling of the engine is provided not only by convection but also by a change of the state of the coolant. The use of such evaporative systems for the cooling of engines of motor vehicles is increasing and in such systems the conventional safety device described above is not suitable.